Model covering tool



- June 4, 1968 E. .1. LIND MODEL COVERING TOOL Filed Sept. 7, 1965 FIG.4

r m, M mm m ML J N m [WM United States Patent 3,386,727 MODEL COVERING TOOL Eldon J. Lind, 11661 Newbury Road, Los Alamitos, Calif. 90720 Filed Sept. 7, 1965, Ser. No. 485,399 4 Claims. (Cl. 26152) ABSTRACT OF THE DISCLOSURE The present invention comprises a device for holding a sheet of pliable material in pressure contact with a portion of a model to permit application of a film-forming liquid to the taut sheet material; each of the side edges of the sheet is clamped between a pair of hinged strips, and each pair of hinged strips is held in clamping position by resilient clips.

For many years, particularly in the building of model aircraft, the models have been formed from a framework or skeleton of balsa wood, or other lightweight material, which are subsequently covered with a pliable sheet material such as silk, or the like. After being placed in taut contact with the framework of the model aircraft the sheet material is coated with a film-forming liquid, which after it has dried or polymerized, adheres the taut silk, or other sheet material, to the framework, with the dried or polymerized film serving to strentghen the silk sheet or other pliable material covered thereby, as well as protecting the sheet from snags or other damages.

In building models, particularly miniature aircraft, a particularly annoying problem encountered is that of holding the thin, light silk sheet material in a taut condition over the framework of the model, such as a wing section, or a part of the fuselage, or other components thereof.

A primary object in devising the present invention is to provide a device by means of which opposite edge portions of a sheet of pliable material can be so removably gripped that the material between the gripped edges thereof is maintained in taut pressure contact with a portion of a model to permit application of a film-forming liquid to the taut sheet material to adhere same to the aircraft framework, which liquid serves to strengthen the sheet material after it has dried or polymerized into a solid film.

Another object of the invention is to provide a model covering tool of relatively simple structure, which can be fabricated from standard, commercially available materials, requires no elaborate plant facilities for the production thereof, is easy to use, and can be retailed at a sufficiently low price as to encourage its widespread use.

These and other objects and advantages of the invention will become apparent from the following description thereof, and from the accompanying drawing illustrating the same, in which:

FIGURE 1 is a perspective view of the model covering tool, showing a section of a model aircraft wing so disposed relative thereto that the wing can be covered by a taut sheet of pliable material;

FIGURE 2 is a transverse cross-sectional view of a portion of the tool shown in FIGURE 1, taken on the line 2-2 thereof;

FIGURE 3 is a transverse cross-sectional view of the tool illustrated in FIGURE 1, taken on the same line as in FIGURE 2, but with the tool gripping an edge portion of a sheet of pliable material; and

FIGURE 4 is an end elevational view of the invention shown in FIGURE 1, illustrating the manner in which opposite edge portions of a sheet of pliable material are removably gripped, with the sheet held in taut pressure contact with a portion of a model.

3,386,727 Patented June 4, 1968 ice With continued reference to the drawing for the general arrangement of the invention, it will be seen in FIGURE 1 to include two elongate, parallel, transversely spaced bases A and B that are preferably formed from a relatively heavy material, such as steel, iron, or the like. First and second strips 10 and 12 extend longitudinally along the uppenadjoining surfaces of bases A and B respectively.

First and second elongate plates C and D, also formed of a heavy material such as iron or steel, are disposed along the outer longitudinal edges of bases A and B. A number of hinges 14 of a conventional design are afiixed to the upper outer surfaces of the bases A and B, as well as to the upper inner surfaces of the plates C and D, as shown in FIGURE 1. The hinges 14 are afiixed to the bases A and B and the plates C and D by conventional means, such as screws, tacked welding, or the like.

Third and fourth elongate strips 16 and 18 of a resilient material are mounted on the upper outer edge surfaces of plates C and D respectively (FIGURE 1), with the third and fourth strips overlying the first and second strips 10 and 12, as partially shown in FIGURE 3, when the plates C and D are pivoted inwardly to overlie the bases A and B. The resilient strips 10, 12, 16 and 18 are preferably formed from a resilient foamed material, such as Styrafoam, manufactured by the Dow Chemical Company, of Midland, Mich.

The first and second bases A and B are laterally adjustable relative to one another, as will later be explained, and are illustrated in FIGURE 1 as being separated by a distance 20, which is such that a portion of a model aircraft, in this instance a wing section 22 thereof, can be removably disposed between the two bases. The first base A, as shown in FIGURE 1, includes two uprights 24 affixed to the inner end portions 26 thereof.

At a substantial distance above the first base A the uprights 24 develop into two elongate legs 28 that are parallel to the surfaces 30 on which the bases A and B rest. Two posts 32 project upwardly from the inner end portions 34 of base B, which portions are in lateral alignment with the uprights 24. Two tubular sleeves 36 are mounted on the upper ends of post 32 that slidably engage the legs 28, as may be seen in FIGURE 1. Two thumb screws 38 are mounted in tapped bores (not shown) formed in the sleeves 36, and these thumb screws frictionally grip the legs 28 to the extent that the bases A and B are held in desired spacing 20 relative to one another. The width of the space 20 depends on the width of the portion 22 of the model aircraft disposed between bases A- and B.

The use and operation of the invention are most simple. The thumb screws 38 are first loosened to permit the legs 28 to slide relative to the sleeve 36, and the bases A and B then are adjusted to arrange a space 20 therebetween of sufficient width to permit a desired portion 22 of a model aircraft to be disposed therein, as shown in FIGURE 1.

Thereafter, a sheet of pliable material 40 is laid over the upper surface of the model portion 22, as well as over the first and second elongate resilient strips 12. The plates C and D may then be pivoted inwardly to permit the third and fourth strips 16 and 18 to overlie the first and second strips 10 and 12 respectively, and frictionally grip the opposite longitudinal edge portions of the sheet 40 therebetween. One of the edge portions of the sheet 40 is shown in FIGURE 3 gripped by the second and fourth resilient strips 12 and 18, respectively. The second longitudinal edge portions of the sheet 40 are also shown in FIGURE 4 gripped by the first and third resilient strips 10 and 16 and second and fourth resilient strips 12 and 18.

A number of U-shaped resilient clips 42 are provided, as shown in FIGURE 3, which may be snapped over the plates C and D when they are overlying the bases A and B, to hold the first and third strips 18 and 16 and second and fourth strips 12 and 13 in gripping contact with opposite longitudinal edge portions of the sheet 40. With the opposite longitudinal edge portions of sheet 49 so gripped, either the base A is moved relative to the base B, or vice versa, to increase the Width of the space 20 and forcibly bring the sheet into pressure contact with the upper part of the aircraft portion 22 (FIGURE 4) whereby the sheet material is tautly stretched thereacross. After the bases A and B have been so positioned, the thumb screws 38 are tightened to hold the bases in this spaced relationship.

A film-forming liquid, such as a lacquer, or the like, commonly referred to as dope, is applied to the upper surface of the portion 22, with the liquid after it is dried or polymerized, adhering the sheet material 40 to the portions. After the liquid (not shown) has dried or polymerized, the clips 42 are removed from engagement With the plates C and D and bases A and B to permit the plates to be pivoted into the positions shown in FIGURE 1. The portion 22 is then removed from between the bases A and B and the surplus sheet material 40 extending outwardly from the portion 22 is trimmed therefrom.

Although the present invention is fully capable of achieving the objects and providing the advantages hereinbefore mentioned, it is to be understood that it is merely illustrative of the presently preferred embodiment thereof and I do not mean to be limited to the details of construction herein shown and described, other than as defined in the appended claims.

I claim:

l. A device for holding a sheet of pliable material in taut pressure contact with a portion of a model aircraft structure to permit application of a film-forming liquid to said sheet to adhere said sheet to said portion, including:

(a) first and second parallel, transversely spaced, elongate bases formed from a relatively heavy material;

(b) first and second elongate strips of a resilient material adhered to the upper adjoining longitudinal surfaces of said bases;

(c) first and second elongate plates;

((1) first and second hinge means for connecting said first and second plates to the outer longitudinal edge portions of said first and second bases;

(e) third and fourth elongate strips of a resilient material adhered to the upper, outer longitudinal surface portions of said plates, and adapted to overlie said first and second strips when said first and second plates are pivoted inwardly over said first and second bases;

(f) first means for holding said first and second bases in a desired transverse spaced relationship to permit said portion of said aircraft structure to be disposed therebetween, comprising:

( 1) a plurality of longitudinally spaced uprights 'aifixed to said first base;

(2) a plurality of longitudinally spaced posts afiixed to said second base and transversely alignable with said uprights;

(3) a plurality of rigid legs that are parallel to said first base and extend from the upper ends of said uprights towards said posts;

(4) a plurality of sleeves mounted on the upper ends of said posts which slidably engage said legs, with each of said sleeves having a tapped bore formed therein; and

(5) a plurality of thumb screws that engage said tapped bores, which screws when tightened on said legs hold said first and second bases in a desired transverse spacing; and

(g) second means for holding said first and second plates in overlying pressure exerting positions on said first and second bases to permit said first and third, and said second and fourth resilient strips to frictionally grip opposite sides of said pliable sheet therebetween and hold said sheet in taut pressure contact with said portion of said model aircraft disposed between said first and second bases.

2. A device as defined in claim 1 wherein said second means comprise a plurality of resilient members that exert a downward force on said first and second plates, when so disposed as to overlie said first and second bases.

3. A device as defined in claim 1 wherein said second means comprise a plurality of generally U-shaped resilient clips which tend to force said first and second plates into pressure contact with said first and second bases when mounted on said plates and bases.

4. A device as defined in claim 1 wherein said strips are formed from a foamed resin.

References Cited UNITED STATES PATENTS 1,506,368 2/1923 Fancher 26954 1,913,710 1/1931 Huff 38-402 2,288,492 9/1940 Silvernail 38-1024 FOREIGN PATENTS 6,693 5/1896 Great Britain.

LESTER M. SWINGLE, Primary Examiner. D. R. MELTON, Assistant Examiner. 

